Sliding caliper disc brakes

ABSTRACT

In a disc brake such as a sliding caliper disc brake, the caliper is mounted for movement with respect to a torque plate by pin assemblies extending into aligned openings in the caliper and torque plate. The pin assemblies are of multi-part construction, parts of the pin assemblies which provide for movement between the caliper and torque plate being able to remain undisturbed when the caliper is removed from the torque plate. 
     Another feature is that the openings in the caliper or the torque plate are oversize, so that the pin assemblies are received as a free fit, and the pin assemblies are clamped in the oversize openings by interengagement of screw threaded portions. Sliding surfaces are provided either directly by the shanks of pins or by separate bushes which may be resilient. 
     The construction is such that the pin assemblies are relieved of clamping forces and drag forces when the brake is actuated.

This application is a continuation of application Ser. No. 231,913 filedMar. 6, 1972, now abandoned.

The present invention relates to sliding caliper disc brakes.

In disc brakes of the type having a caliper member mounted on a torqueplate member by means of a pair of sliding connections, manufacturinginaccuracies may give rise to misalignment between nominally alignedinterengageable parts of the brake leading to difficulty in initialassembly and possibly to significantly different resistance to slidingbetween the brakes fitted to any one vehicle. Attempts to accommodatesuch misalignment by the use of resilient elements such as rubber busheshave not been wholly satisfactory as a connection which is sufficientlysoft to take up significant misalignment is too soft to support thecaliper properly on the torque plate.

It is an object of the present invention to provide a sliding caliperdisc brake having a caliper mounted on a fixed torque plate by way of asliding connection which, during assembly, permits transverse movementfor proper alignment but which is a rigid connection when the brake isfully assembled.

According to the present invention, there is provided a sliding caliperdisc brake comprising a rotable disc, a torque plate member for fixingto a vehicle frame or the like, a caliper member straddling a minorportion of the periphery of the disc for moving friction pad meansdisposed on opposite sides of the disc into braking engagement with thedisc, portions of the torque plate member being arranged to receivedirectly drag forces experienced by each of the pad means, motor meansin the caliper member for directly urging one pad means onto one side ofthe disc to cause the caliper member to slide relative to the torqueplate member to apply by reaction the opposite pad means to the otherside of the disc, and a sliding connection between the caliper memberand the torque plate member comprising a first component slidablyreceived in an opening in one of the members, a second component passingthrough an oversized opening in the other of said members and screwthreadedly engaging said first component to releasably clamp the sameagainst the other of said members.

When said two components are in loose screw-threaded engagement, saidoversized opening permits the degree of lateral movement of the twocomponents required to align the two components with the opening in saidone of the members. Subsequent tightening of the screw-threadedconnection clamps said components and said members against furtherlateral movement.

The invention will be described further, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a plan view, partly in section, of a sliding caliper discbrake embodying the invention;

FIG. 2 is a front elevation of the brake;

FIG. 3 is a rear elevation thereof;

FIG. 4 is an elevation taken from one side of the brake;

FIG. 5 is an elevation, partly in axial section of the other side of thebrake;

FIG. 6 is an elevation, again partly in section, similar to that of FIG.5, showing a modified embodiment of the invention;

FIGS. 7 to 11 inclusive are fragmentary sectional details of the slidingconnection between the caliper member and the torque plate in stillfurther embodiments of the invention;

FIG. 12 is a sectional elevation of a further embodiment;

FIG. 13 is a rear elevation, partly in section, of the embodiment ofFIG. 12;

FIG. 14 is an elevation, partly in section, of the embodiment of FIG. 12from the other side of the brake;

FIG. 15 is a rear elevation, partly in section, of a still furtherembodiment;

FIG. 16 is a side elevation of the embodiment of FIG. 15; and

FIG. 17 is a detail, in section, of the embodiment of FIG. 16.

Wherever appropriate, like reference numerals are employed throughoutthe drawings to denote like parts.

In the sliding caliper disc brake illustrated in FIGS. 1 to 5 inclusive,a torque plate generally designated 10 has a main radially directedportion 12 extending on one side of a brake disc (not shown), the maintorque plate portion 12 being bifurcated to present a pair of lateralarms situated at respective circumferential end regions of the torqueplate and passing over the brake disc to terminate at the opposite sidethereof in radially downwardly directed end 16. A generally U-shapedcaliper member 18 has a radially directed rear limb 20 connected by anaxial crown portion 22 to a radially directed front limb 24. The crownportion 22 of the caliper passes between the opening defined between thearms 14 of the torque plate and the rear caliper limb 20 connected by anaxial crown portion 22 to a radially directed front limb 24. The crownportion 22 of the caliper passes between the opening defined between thearms 14 of the torque plate and the rear caliper limb 20 carries afriction pad assembly 26 capable of engaging one braking face of thebrake disc whilst the front caliper limb 24 carries a second frictionpad assembly 28 arranged to be engageable with the opposed braking faceof the brake disc. The caliper limb 20 is also integrally formed with apair of circumferentially spaced hydraulic cylinders 30, each carrying apiston 32 displaceable responsive to fluid pressure within its cylinderin order directly to displace the friction pad assembly 26 intoengagement with the brake disc. An independent hydraulic circuit may beprovided for each hydraulic cylinder 30 and the cylinder bore sizes maybe unequal. By virtue of the reaction resulting from engagement of thefriction pad assembly with the brake disc, the caliper member is causedto slide relatively to the torque plate 10, thereby to engage thefriction pad assembly 28 with the opposite face of the brake disc.

For the purpose of establishing the required sliding connection betweenthe torque plate and the caliper member, the latter is provided withcircumferential extensions 34, each of which terminates in an axiallydirected lug 36. The lugs 36 are axially apertured as indicated at 38and the apertures 38 are intended each to register axially with acorresponding axial aperture 40 formed in an adjacent torque plate arm14. Each torque plate aperture 40 receives the shank portion 44 of a pin42 which is passed through it and which extends beyond it on the sideopposite to the head 46 of the pin. The portion 48 of the pin whichextends beyond the aperture 40 is threaded and engages an internallythreaded region of a bush 50 over which the caliper lug 36 is engaged insliding relation. Protective rubber or plastics boots 51 are engagedover the bush 50 and each end of the lug 36 in which it is received inorder to exclude dirt and moisture and to retain the bush in the lug 36.

By virtue of the pin and bush arrangement shown in the drawings, thecaliper member is supported accurately in its mounted position simply bytightening the pins 42 within the bushes 50 to clamp the latter firmlyagainst the end faces of the torque plate arms 14. Removal of thecaliper member 18 from the torque plate for pad replacement purposes isequally simply effected by releasing the pins 42 and lifting the calipermember out from the opening defined between the torque plate arms 14. Itwill be seen that the bushes 50 remain at all times retained within thecaliper member, so that at no time are the sliding surfaces disturbed orseparated. However, in order to protect the sealing boots 51, bothduring mounting of the caliper member 18 on the torque plate 10 andduring its removal therefrom, the bushes 50 must be restrained fromrotation and are shown in FIG. 1 as being formed with holes 52engageable by a simple tool such as a screwdriver or a tommy bar.Alternatively, the bush may be provided with a shoulder engageable by atool such as a spanner by which rotation of the bush may be prevented.Any other form of anti-rotation means, may, however, be provided forexample by arranging a key and keyway between the lugs 36 and bush 50.

The brake illustrated in FIG. 6 of the drawings differs from thatalready described principally in that the caliper mounting pins arescrewed into the torque plate. In this embodiment of the invention, thelateral lugs 36 of the caliper member 18 are fitted with bushes 52 whichare internally plain and a pin 54 having a head 56 and a plain shankportion 58 is passed through each bush to extend beyond the same at itsfree end. The free end of the pin 54 is threaded as indicated at 60 andengages within a complementarily threaded aperture 62 of a torque plate64. The caliper member 18 is thus readily mounted on the torque plate 64by passing the pin through the bush and when the pin is tightened withinthe torque plate aperture 62, the bush is securely clamped between thetorque plate and the head 56 of the pin. In all other respects, theconstruction and operation of this embodiment of the invention issimilar to that already described.

In the above embodiments and in the embodiments described hereinafter,the disc brakes may be adapted for use in commercial vehicles by formingthe torque plate as a carrier for mounting on the vehicle axle.

FIGS. 7 to 11 of the drawings illustrate further modifications of theinvention, wherein the sliding surfaces for the caliper member areprovided directly by the pins rather than by bushes but wherein separateclamping screws are provided (rather than the pins themselves) forclamping the pins to the torque plate, thereby enabling the pins toremain permanently in the torque plate and thus to protect and preservethe operative relationship of the sliding surfaces.

In FIG. 7, a pin 70 is received as a sliding fit in aperture 72 of atorque plate 74 and projects at one end from the aperture 72 toterminate in an enlarged diameter head 76. The projecting end of the pin70 is axially bored and threaded as indicated at 78 in order to receivea clamping screw 80 which passes through a lug 82 of the caliper member.At its opposite end, the pin 70 has a reduced diameter portion 84 onwhich is mounted a friction ring 86 secured in position by a washer 88and locknut 90, dished spring washers 92 mounted in back-to-backrelation being interposed between the friction ring 86 and washer 88. Inthe operation of the brake, therefore, as the brake friction pads (notshown) wear, the caliper member and hence the pin 70 move to the left asviewed in the drawing, but when the brake is released, the calipermember is recentred by the spring washers 92. When the pad wear exceedsa predetermined amount, however, the locknut 90 moves the friction ring86 in the aperture 72, with the result that the caliper member adopts anew position, thus conserving the fluid requirement of the hydraulicmotor for full brake application.

The brake illustrated in FIG. 8 differs from that of FIG. 7 only in thatthe spring washers 92 are omitted.

The brake shown in FIG. 9 achieves a result similar to that of FIGS. 7and 8 by substituting a resilient e.g. elastomeric sealing ring 94 atthe inner end of the pin 70 in place of the friction ring 86.

It will be noted that in the brakes of FIGS. 8 and 9, the pin 70 isreceived in a blind aperture 72 of the torque plate, so that only asingle sealing boot 96 is required to exclude dirt and moisture from thesliding surfaces of the pin and the caliper member. A similararrangement is provided in FIG. 10, but in this instance, the pin 70 hasan axial bore 98 opening into a radial port 100 formed in a reduceddiameter inner end portion 102 of the pin, enabling air to escape easilyfrom the aperture 72 when the pin is first introduced into it.

Although in all the embodiments of FIGS. 7 to 10, the caliper member issupported on one side only of the torque plate, FIG. 11 illustrates anarrangement wherein the caliper member is provided with a portionstraddling the torque plate to present a lug 82 at each side thereof andwherein a pin 104 passes through the torque plate aperture 72 to extendon each side of the torque plate. Each end of the pin 104 is thenaxially bored and threaded to receive a clamping screw 80 passingthrough a respective caliper lug 82, whereby the caliper member isenabled to be supported on both sides of the torque plate.

In addition to hydraulic actuation, the sliding caliper disc brake shownin FIGS. 12 to 14 provides for mechanical actuation by way of a peg 110which incorporates an automatic adjuster mechanism. The peg 110 abutsagainst the hydraulic piston 112 and is displaceable by rotation of ashaft 114 coupled to the peg 110 by a dolly 116. The shaft 114 isintended to be connected to a vehicle handbrake linkage.

As is clear from FIG. 13, the pads 118 are guided by arms 120 of thetorque plate 122 so that drag forces are directly transmitted to thetorque plate during brake actuation. The pads are additionally guided ona removable pin 124 mounted in the caliper and extending through anoversize opening in a lug 126 extending from each of the pad backplates. To restrain movement of the pads in the caliper, a leaf spring128 is arranged with its ends abutting the pad back plates at 130 andintermediate regions abutting against projecting portions of the caliperat 132. The removable pin 124 spans an opening 134 in the top of thecaliper, the opening 134 permitting visual inspection of the padfriction material when the disc brake is assembled in a vehicle.

FIG. 14 shows one of the pins by which the caliper housing is mounted onthe torque plate. The pin 136 extends into an oversize bore 138 and isprovided with a pair of resilient bushes 140, of for example, plasticsmaterial, which are arranged between a shoulder 143 formed on the pinand a washer 141 secured to the end of the pin by a fastener 142. As inthe arrangments shown in FIGS. 7 to 11, a separate clamping screwpassing as a free fit through the bore in a caliper lug 146 secures thepin 136 to the caliper. The lug 146 is clamped between the head 144 ofthe clamping screw and an enlarged diameter head 148 on the pin 136.

The resilient bushes 140 serve to accommodate such misalignment of thebores in the lug and torque plate as may arise through flexing of thetorque plate when the brake is under extreme load. In one modification(now shown), the resilient bushes 140 are replaced by resilient tubularmembers seated in flutes formed in the pin.

The embodiment of FIGS. 15 to 17 incorporates a unitary caliper, thatis, a caliper formed in one piece, in which the outer limb is cut awayto permit machining of the hydraulic cylinder bores without thenecessity for splitting the caliper. As in previously describedembodiments, both pad back plates 150 are in sliding engagement witharms 152 on the torque plate so that circumferential drag is taken updirectly by the torque plate thus freeing the mounting pins ofcircumferential load.

Unlike the arrangement illustrated in FIG. 14 in which the pins 136extend across both pads and must therefore be widely spaced apart toclear the disc when the brake is assembled in a vehicle, the mountingpins 136 in the embodiment of FIGS. 15 to 17 are disposed rearwardly ofthe directly actuated pad. The pins 154 may thus be brought closertogether to lie within the periphery of the disc resulting in reducedcircumferential dimension of the caliper and torque plate. With theexception of the disposition of the pins, relative to the pads, themeans by which the caliper is mounted on the torque plate is similar tothat of FIG. 14 so that like reference numerals have been used in FIGS.16 and 17. One further advantage of the embodiment of FIGS. 15 to 17 isthat the centre of gravity lies within the length of the pins 136 sothat the caliper is better balanced than is the cantilever-mountedcaliper of FIG. 14.

We claim:
 1. A sliding caliper disc brake comprising a rotatable disc, atorque plate member for fixing to a vehicle frame or the like, a calipermember straddling a minor portion of the periphery of the disc formoving friction pad means disposed on opposite sides of the disc intobraking engagement with the disc, portions of the torque plate memberbeing arranged to receive directly drag forces experienced by each ofthe pad means, motor means in the caliper member for directly urging onepad means onto one side of the disc to cause the caliper member to sliderelative to the torque plate member to apply by reaction the oppositepad means to the other side of the disc, and a sliding connectionbetween the caliper member and the torque plate member comprising afirst component slidably received in an opening in one of the members, asecond component passing through an oversized opening in the other ofsaid members and screw threadedly engaging said first component toreleasably clamp the same against the other of said members, saidoversized opening providing sufficient clearance for relative transversemovement between said second component and the other of said members. 2.The brake of claim 1 wherein said one of said members is the torqueplate member and the other of said members is the caliper member.
 3. Thebrake of claim 1 including resilient means between the sliding surfacesof said first component and said one of said members.
 4. The brake ofclaim 1 having a pair of said sliding connections and includingresilient means between the sliding surfaces of one of said pair.
 5. Thebrake of claim 1 including means for holding one of said componentsagainst rotation whilst the other component is rotated during formationand release of said sliding connection.
 6. The brake of claim 1 whereinsaid second component has a formation by which said second component maybe rotated and said first component has a formation by which said firstcomponent may be held against rotation and wherein said formations areboth on the same side of the disc.
 7. A sliding caliper disc brakecomprising a rotatable disc, a torque plate member adapted for fixing toa vehicle frame or the like, a caliper member slidable relative to saidtorque plate member for moving friction pads disposed on opposite sidesof said brake disc into braking engagement with said disc, portions ofthe torque plate member being arranged to receive directly drag forcesexperienced by each pad means, at least one removable pin meansconstructed in two parts, one of said parts having a sliding surface ina complementary opening in one of said members, the other of said partspassing with a clearance fit through an oversize opening in the other ofsaid members and being threadedly engaged with the first part of saidpin means, said clearance fit allowing transverse movement of said otherpart in said opening, said first and second pin parts having opposedabutment surfaces engaging said other member at opposite ends of saidoversized opening and being constructed and arranged that when said pinparts are lockingly screwed together the abutment surfaces clamp betweenthem the opposite sides of said other member with sufficient force toprevent said transverse movement of said pin part in said oversizedopening and thereby rigidly fixing said pin part in said oversizedopening.
 8. A sliding caliper disc brake according to claim 7 whereinsaid one of said members is said torque plate member and said other ofsaid members is said caliper member.
 9. A sliding caliper disc brakeaccording to claim 7 wherein said one of said members is said calipermember and said other of said members is said torque plate member.
 10. Asliding caliper disc brake according to claim 7 including resilientmeans between the sliding surfaces of said pin means and said one ofsaid members.
 11. A sliding caliper disc brake according to claim 7having a pair of said removable pin means and including resilient meansbetween the sliding surfaces of one of said pair.
 12. A sliding caliperdisc brake according to claim 7 including means for holding one of saidparts against rotation whilst the other of said parts is rotated duringformation and release of the sliding connection between said members.13. A sliding caliper disc brake according to claim 7 wherein saidsecond part has a formation by which said second part may be rotated andsaid first part has a formation by which said first part may be heldagainst rotation and wherein said formations are both on the same sideof the disc.
 14. A sliding caliper disc brake according to claim 7wherein said complementary opening is closed at one end and whereinsealing means seal the other end.
 15. A sliding caliper disc brakecomprising a rotatable disc, a torque plate member for fixing to avehicle frame or the like, a caliper member straddling a minor portionof the periphery of the disc for moving friction pad means disposed onopposite sides of the disc into braking engagement with the disc,portions of the torque plate member being arranged to receive directlydrag forces experienced by each of the pad means, motor means in thecaliper member for directly urging one pad means onto one side of thedisc to cause the caliper member to slide relative to the torque platemember to apply by reaction the opposite pad means to the other side ofthe disc, and a sliding connection between the caliper member and thetorque plate member comprising a first component slidably received in anopening in one of the members, and a second component passing through anopening in the other of said members and being laterally adjustabletherein into alignment with said first component, said first and secondcomponents having complementary screw-threaded portions by which saidfirst and second components are locked together to clamp said firstcomponent to said other of said members.
 16. A sliding caliper discbrake comprising a rotatable disc, a torque plate member for fixing to avehicle frame or the like, a caliper member straddling a minor portionof the periphery of the disc for moving friction pad means disposed onopposite sides of the disc into braking engagement with the disc,portions of the torque plate member being arranged to receive directlydrag forces experienced by each of the pad means, motor means in thecaliper member for directly urging one pad means onto one side of thedisc to cause the caliper member to slide relative to the torque platemember to apply by reaction the opposite pad means to the other side ofthe disc, and a sliding connection between the caliper member and thetorque plate member comprising a first component slidably received in anopening in one of the members, and a second component having ascrew-threaded portion and passing through an opening in the other ofsaid members and being laterally adjustable therein into alignment witha complementary screw-threaded opening in said first component, saidfirst and second components being locked together by screw-threadedengagement to clamp said first component to said other of said members..Iadd.
 17. A vehicle brake comprising a carrier member for fixing to avehicle frame, a caliper member for straddling a rotatable disc, and anactuator for urging a first friction pad onto one surface of the disc tocause the caliper member to move relative to the carrier member andapply a second friction pad to an opposite surface of the disc, thebrake having between the carrier member and the caliper member a slidingconnection comprising a pair of pins each of which is slidable in andcircumferentially surrounded by a respective oversized opening in one ofthe members and secured to the other of said members, both of said pinsbeing relieved of transmitting braking forces from said friction pads tosaid carrier member by means which transmit such braking forces directlyor indirectly from both of said pads to the carrier member, theoversized openings being sufficiently greater than the correspondingdimension of said pins as to permit lateral movement of the latterduring actuation of the brake, said pins sliding in said openings duringeach actuation of the brake said brake including resilient biasing meanscausing said pins to adopt eccentric positions in their respectiveoversized openings with said pins in sliding contact with a portion ofthe walls of said oversized openings, said resilient biasing meansacting in such a direction as to maintain, at least when the brake is ina released condition, freedom of lateral movement of each pin in itsrespective oversized opening in a direction generally towards the otheroversized opening, whereby to permit the sliding connection toaccommodate deformation of the carrier member during brake application..Iaddend. .Iadd.18. A brake according to claim 17 in which said pins aresecured to said caliper member and in which said resilient biasing meansare operable to urge said caliper member generally radially outwardly ofthe disc. .Iaddend. .Iadd.19. A brake according to claim 18 in whichsaid resilient biasing means is a leaf spring engaging said calipermember. .Iaddend. .Iadd.20. A brake according to claim 19 in which saidleaf spring is adapted to engage the friction pads so as to urge saidfriction pads radially inwardly against abutment surfaces on saidcarrier member. .Iaddend. .Iadd.21. A brake according to claim 17 inwhich at least one of said pins carries a resilient sheath surroundingsaid pin over a major portion of its axial distance; which provides thesliding surface of the pin. .Iaddend. .Iadd.22. A vehicle brakeaccording to claim 17 wherein said oversized opening comprises a blindbore in said one of said members. .Iaddend. .Iadd.23. A vehicle brakecomprising a carrier member for fixing to a vehicle frame, a calipermember for straddling a rotatable disc, and an actuator for urging afirst friction pad onto one surface of the disc to cause the caliper tomove relative to the carrier member and apply a second friction pad toan opposite surface of the disc, the brake having between the carriermember and the caliper member a sliding connection comprising a pair ofpins each of which is slidable in and circumferentially surrounded by arespective opening in one of the members and secured to the other ofsaid members, both of said pins being relieved of transmitting brakingforces from said friction pads to said carrier member by means whichtransmit such braking forces directly or indirectly from both of saidpads to the carrier member, at least one of said openings beingsufficiently oversized to permit radial movement of its respective pinduring actuation of the brake, and at least one of said pins beingsecured to said other member in such a manner as to be laterallyadjustable with respect to said other member whereby to permit accuratelateral positioning in the or each oversized opening of the pin or pins..Iaddend. .Iadd.24. A brake according to claim 23 in which the or eachlaterally adjustable pin is secured to said other member by releasableclamping means comprising a clamping screw in screw-threaded engagementwith the pin and passing through an opening in said other member so asto clamp the pin against said other member, said opening in said othermember being sufficiently oversized as to permit lateral movement ofsaid clamping screw in said opening prior to rigid clamping of the pinagainst said other member by said clamping screw. .Iaddend. .Iadd.25. Avehicle brake comprising a carrier member for fixing to a vehicle frame,a caliper member for straddling a rotatable disc, and an actuator forurging a first friction pad onto a one surface of the disc to cause thecaliper to move relative to the carrier member and apply a secondfriction pad to an opposite surface of the disc, the brake havingbetween the carrier member and the caliper member a sliding connectioncomprising a pair of pins each of which is slidable in andcircumferentially surrounded by a respective oversized opening in one ofthe members and secured to the other of said members, at least one ofsaid pins being secured to said other member in such a manner as to belaterally adjustable with respect to said other member, both of saidpins being relieved of transmitting braking forces from said frictionpads to said carrier member by means which transmit such braking forcesdirectly or indirectly from both of said pads to the carrier member, theoversized openings being sufficiently greater than the correspondingdimension of said pins as to permit radial movement of the latter duringactuation of the brake, said braking including resilient biasing meanscausing said pins to adopt eccentric positions in their respectiveoversized openings with said pins in sliding contact with a portion ofthe walls of said oversized openings, said resilient biasing meansacting in such a direction as to maintain, at least when the brake is ina released condition, freedom of lateral movement of each pin in itsrespective oversized opening in a direction generally towards the otheroversized opening, whereby to permit the sliding connection toaccommodate deformation of the carrier member during brake application..Iaddend. .Iadd.26. A brake according to claim 25 in which said pins aresecured to said caliper member and in which said resilient biasing meansare operable to urge said caliper member generally radially outwardly ofthe disc. .Iaddend. .Iadd.27. A brake according to claim 26 in whichsaid resilient biasing means is a leaf spring engaging said calipermember. .Iaddend. .Iadd.28. A brake according to claim 27 in which saidleaf spring is adapted to engage the friction pads so as to urge saidfriction pads radially inwardly against abutment surfaces on saidcarrier member. .Iaddend. .Iadd.29. A brake according to claim 25 inwhich at least one of said pins carries a resilient sheath whichprovides the sliding surface of the pin. .Iaddend. .Iadd.30. A brakeaccording to claim 25 in which the or each laterally adjustable pin issecured to said other member by releasable clamping means. .Iaddend..Iadd.31. A brake according to claim 30 in which said clamping meanscomprises a clamping screw in screw-threaded engagement with the pin andpassing through an opening in said other member so as to clamp the pinagainst said other member, said opening in said other member beingsufficiently oversized as to permit lateral movement of said clampingscrew in said opening prior to rigid clamping of the pin against saidother member by said clamping screw. .Iaddend. .Iadd.32. A vehicle brakecomprising a carrier member for fixing to a vehicle frame, a calipermember for straddling a rotatable disc, and an actuator for urging afirst friction pad onto one surface of the disc to cause the caliper tomove relative to the carrier member and apply a second friction pad toan opposite surface of the disc, the brake having between the carriermember and the caliper member a sliding connection comprising a pair ofpins each of which is slidable in and circumferentially surrounded by arespective opening in one of the members and secured to the other ofsaid members, both of said pins being relieved of transmitting brakingforces from said friction pads to said carrier member by means whichtransmit such braking forces directly or indirectly from both of saidpads to the carrier member, at least one of said openings beingsufficiently oversized to permit radial movement of its respective pinduring actuation of the brake, said pins sliding in said openings duringeach actuation of the brake and the pin extending into the oversizedopening or at least one of the pins extending into the two oversizedopenings carrying a resilient sheath which provides the sliding surfaceof the pin, and resilient biasing means acting to cause said pin andsheath to adopt eccentric positions in their respective oversizedopenings, at least when the brake is in a released condition, tomaintain freedom of lateral movement of each pin in its respectiveoversized opening in a direction generally towards the other oversizedopening, whereby to permit the sliding connection to accommadatedeformation of the carrier member during brake application. .Iaddend..Iadd.33. A vehicle brake comprising a carrier member for fixing to avehicle frame, a caliper member for straddling a rotatable disc, and anactuator for urging a first friction pad onto one surface of the disc tocause the caliper to move relative to the carrier member and apply asecond friction pad to an opposite surface of the disc, the brake havingbetween the carrier member and the caliper member a sliding connectioncomprising a pair of pins each of which is slidable in andcircumferentially surrounded by a respective opening in one of themembers and secured to the other of said members, both of said pinsbeing relieved of transmitting braking forces from said friction pads tosaid carrier member by means which transmit such braking forces directlyor indirectly from both of said pads to the carrier member, at least oneof said openings being sufficiently oversized to permit relative radialmovement between said opening and its respective pin during actuation ofthe brake, said pins sliding in said openings during each actuation ofthe brake and a resilient sheath surrounding that pin which extends intosaid at least one oversized opening, said sheath providing a slidingsurface for said pin within said oversized opening, and resilientbiasing means acting to cause said pin and sheath to adopt eccentricpositions in their respective oversized openings, at least when thebrake is in a released condition, to maintain freedom of lateralmovement of each pin in its respective oversized opening in a directiongenerally towards the other oversized opening, whereby to permit thesliding connection to accommadate deformation of the carrier memberduring brake application. .Iaddend.